Mr Allister had written to the direct rule security minister last year requesting that he and several party colleagues were considered under the Limited Home Protection Scheme, which provides additional security for those deemed to be under threat.

However, in his reply to the TUV leader’s request, Mr Goggins mixed up the security assessment for Mr Allister and for another TUV member.

A furious Mr Allister said that the slip-up demonstrated “indifference over recent republican terrorist threats to TUV members”.

“I am appalled to have received a letter from Paul Goggins concerning a colleague in which the security assessment relied upon does not even relate to him, but to someone else,” he said.

“If Paul Goggins read the letter before he signed it, then it is hard to understand how he made such a schoolboy error.

“It hardly instils confidence in the manner or seriousness with which the NIO addresses what should be important issues.

“How could a security minister supposedly giving a considered response on a serious issue not even notice that the assessment relied on didn’t even relate to the person in question?”

An NIO spokeswoman said: “There was an error in a letter to Mr Allister in that Mr Allister’s name was inadvertently used once rather than the name of his colleague.”

However, the spokeswoman stressed: “The information provided to Mr Allister was correct and the minister will be writing to him to apologise for the error.”